For crops having heavy foliage, such as, potatoes, tomatoes, sugar beets, beans, cabbage, broccoli, cotton, etc., it is commonly necessary to spray chemicals for the control of insects and diseases in such a way that the chemicals reach the underside of the leaf. This is a difficult problem for most sprayer designs. U.S. Pat. No. 2,770,501 discloses a mechanism which, when used on a sprayer, accomplishes coverage on the underside of leaves. The mechanism, however, has been somewhat inefficient and, consequently, not widely accepted.
U.S. Pat. No. 2,770,501 discloses use of a wing placed in a conduit through which air is forced. Oppositely directed streams of liquid chemical are ejected into a triangular opening extending from top to bottom through the central part of the wing. The base portion of the triangular opening forms the leading edge of a second wing profile which extends rearwardly to conform to the profile of the larger wing profile. Although chemical trails rearwardly along the upper and lower surfaces of the wing to be atomized within the vortex and subsequent turbulent flow trailing the wing, a significant amount of chemical apparently does not properly follow this pattern. Large droplets or amounts of chemical drop onto the ground and are not properly utilized. Apparently, the impacting of the two oppositely directed streams against one another cause certain amounts of chemicals to be ejected from the reduced pressure region so that the chemical does not trail along the wing surfaces.